Management of adverse reactions to bacille Calmette-Guérin vaccine

Complications of the Bacillus Calmette-Guerin vaccine as an early warning sign of inborn errors of immunity: a report of 197 patients

Background

According to the WHO's recommendation for developing countries, Bacillus Calmette-Guerin (BCG) vaccination has been implemented in some countries as part of national vaccination programs at birth. Although it is generally considered safe, some complications may occur; including BCGitis (local) or BCGosis (systemic), ranging from mild like local abscesses to fatal impediments like osteomyelitis and disseminated BCG infection. This study aimed to determine the spectrum of inborn errors of immunity (IEI) in BCG-vaccinated neonates experiencing local or systemic complications.

Methods

In this cross-sectional study, we investigated Iranian children referred to the Immunology, Asthma, and Allergy Research Institute (IAARI) between 2007-2023 for suspected immunodeficiency. Medical history was recorded, and primary screening tests for immunodeficiency were conducted for all cases. For suspected cases, more advanced immunologic investigations were performed to reach a definitive diagnosis. Furthermore, the study incorporated the documented genetic findings of the patients under investigation. All patients with inborn error of immunity who had a history of BCG vaccine complications within the first year of vaccination were enrolled in the study.

Results

We investigated 3,275 cases suspected of IEI, identifying197 patients with both IEI and BCG vaccine complications. Among these, 127 (64.5%) were male. Symptoms began at or before 3 months of age in 64.8% of the cases, and parental consanguinity was reported in 79.2%. Genetic diagnoses were confirmed in 108 patients. Of the 197 patients, 108 (54.8%) had BCGitis, while 89 (45.2%) experienced systemic complications (BCGosis). A family history of IEI, BCG-related complications, and unexplained deaths were observed in 20.3%, 12.2%, and 29.9% of cases, respectively. Furthermore, 46.2% had at least one of these three risk factors in their history.

Conclusions

Early BCG vaccine complications may indicate an underlying immunodeficiency, particularly when there is a positive family history of BCG complications, immunodeficiency, or unexplained deaths. Nation-wide vaccination protocols should address this issue by delaying inoculation to allow for immunological screening of suspected immunodeficient patients, thereby preventing BCG vaccine-related morbidity and mortality.

The mark of success: The role of vaccine-induced skin scar formation for BCG and smallpox vaccine-associated clinical benefits

Skin scar formation following Bacille Calmette-Guérin (BCG) or smallpox (Vaccinia) vaccination is an established marker of successful vaccination and 'vaccine take'. Potent pathogen-specific (tuberculosis; smallpox) and pathogen-agnostic (protection from diseases unrelated to the intentionally targeted pathogen) effects of BCG and smallpox vaccines hold significant translational potential. Yet despite their use for centuries, how scar formation occurs and how local skin-based events relate to systemic effects that allow these two vaccines to deliver powerful health promoting effects has not yet been determined. We review here what is known about the events occurring in the skin and place this knowledge in the context of the overall impact of these two vaccines on human health with a particular focus on maternal-child health.

The Spectrum of Bacille Calmette-Guérin Diseases in Children-A Decade of Data from Neonatal Vaccination Settings

In this paper, we present a multicentre record-based descriptive study used to estimate the incidence and characterize the spectrum of confirmed bacille Calmette–Guérin (BCG) vaccine-related disease among children in Oman. This study included all children (age ≤ 14 years) who had culture and/or polymerase chain reaction (PCR)-confirmed BCG disease from January 2006 to December 2018, as identified from Central Public Health Laboratory data and International Classification of Diseases coding of an electronic patient information system. In total, 88 children confirmed to have BCG disease were included in the study, making an average incidence of 9.2 cases per 100,000 vaccinated neonates. The males comprised 65.9%, Omanis 93.2%, and the median age of presentation was 4 months in children with BCG disease. The most common type of disease was BCG abscesses (72.4%). Children with immunodeficiency and those presenting within 6 months were found to have a more severe and disseminated disease. In total, 28 children had immunodeficiency. The age of presentation and type of BCG disease was significantly associated with immunodeficiency status. The majority of cases required therapy (both medical and surgical) and recovered well. The incidence of laboratory-confirmed BCG vaccine-related disease was low in Oman supporting continuing the use of the BCG vaccination practice at birth.

Evaluation of patients with primary immunodeficiency associated with Bacille Calmette-Guerin (BCG)-vaccine-derived complications

BACKGROUND

Bacille Calmette-Guerin (BCG) vaccination has a great impact on the prevention of severe complications of tuberculosis. However, in patients with primary immunodeficiencies (PID), it can lead to severe complications such as severe combined immunodeficiency, chronic granulomatous disease, and Mendelian susceptibility to mycobacterial disease. This study highlights the demographics, clinical complications and laboratory parameters among PID patients associated with BCG vaccination side effects.

METHODS

One hundred and thirty-seven PID patients with BCGosis were evaluated in this study, based on the complications following BCG vaccination.

RESULTS

The mean age of the patients with BCG complications at the time of the first visit was five years. The within-group comparison of patients showed a highly significant incidence of pneumonia and hepatomegaly in severe combined immunodeficiency patients. Furthermore, the immunologic data showed an increase in the overall rates of lymphocytes such as CD3+, CD4+ and CD8 + T cells in Mendelian susceptibility to mycobacterial disease patients. The level of immunoglobulins has also increased in chronic granulomatous disease patients.

CONCLUSION

The high rate of undiagnosed PIDs predisposes individuals to a high risk of severe side effects as a result of BCG vaccination, as well as infants that are less than one month of age. Therefore, there is a need for early screening and diagnosis of PIDs before exposing unknown PID status patients to BCG vaccination. The benefits of screening and early diagnosis of PID cannot be overemphasized, especially in patients with a previous family history of immunodeficiency.

Mycolicibacterium brumae Is a Safe and Non-Toxic Immunomodulatory Agent for Cancer Treatment

Intravesical Mycobacterium bovis Bacillus Calmette-Guérin (BCG) immunotherapy remains the gold-standard treatment for non-muscle-invasive bladder cancer patients, even though half of the patients develop adverse events to this therapy. On exploring BCG-alternative therapies, Mycolicibacterium brumae, a nontuberculous mycobacterium, has shown outstanding anti-tumor and immunomodulatory capabilities. As no infections due to M. brumae in humans, animals, or plants have been described, the safety and/or toxicity of this mycobacterium have not been previously addressed. In the present study, an analysis was made of M. brumae- and BCG-intravenously-infected severe combined immunodeficient (SCID) mice, M. brumae-intravesically-treated BALB/c mice, and intrahemacoelic-infected-Galleria mellonella larvae. Organs from infected mice and the hemolymph from larvae were processed to count bacterial burden. Blood samples from mice were also taken, and a wide range of hematological and biochemical parameters were analyzed. Finally, histopathological alterations in mouse tissues were evaluated. Our results demonstrate the safety and non-toxic profile of M. brumae. Differences were observed in the biochemical, hematological and histopathological analysis between M. brumae and BCG-infected mice, as well as survival curves rates and colony forming units (CFU) counts in both animal models. M. brumae constitutes a safe therapeutic biological agent, overcoming the safety and toxicity disadvantages presented by BCG in both mice and G. mellonella animal models.

[BCGitis/BCGosis in children: Diagnosis, classification and exploration]

The Bacille Calmette-Guérin (BCG) vaccine is used extensively worldwide, and more than 100 million children are vaccinated each year. This is a live vaccine that protects against severe tuberculosis in children. However, BCG complications, specific to the BCG vaccine, do occur, although the epidemiology differs from one country to another. Nevertheless, these complications are considered to be rare and range from benign local BCGitis to BCGosis, a potentially lethal disseminated disease. Etiologies of BCGitis/BCGosis can be related to the vaccine itself (technical errors, vaccinal strain) or to the patient. Indeed, it is well established that some immunodeficiencies, primary or acquired, can expose the patient to BCG disease. The diagnosis of a BCG disease lies on clinical examination and laboratory results. Recent advances in molecular biology help to distinguish BCG disease from other mycobacterial infections, especially from tuberculosis. When BCG complications have been confirmed, the underlying defect should be investigated, particularly if other features of immunodeficiency are reported, such as recurrent infection, failure to thrive, etc. Prognosis largely depends on the immune status, but also on the management of the BCG disease. Although the therapeutic protocols are still controversial, there are more and more publications on the diagnosis and management guidelines of the disease.

BCG-SSI(®) vaccine-associated lymphadenitis: Incidence and management

BACKGROUND AND OBJECTIVE

There is a high incidence of childhood tuberculosis in Latvia, including children aged less than 1 year, while BCG-associated lymphadenitis is one of the most frequent adverse events requiring surgical treatment. The aim of this study was to analyze the incidence of purulent BCG adenitis through-out the population of Latvia after the introduction of BCG-SSI(®) vaccine and to evaluate the treatment results.

MATERIAL AND METHODS

The study included 194 patients. All patients had received the BCG-SSI(®) vaccine during the first week of life routinely or at a later time according to the indications. The indications for surgical treatment were lymph node destruction also affecting the skin. All patients in this study received surgical treatment - the affected lymph node extirpation.

RESULTS

The mean age of the patients was 5.12±0.96 months. A total of 172 patients had purulent axillar lymphadenitis, 14 had purulent supraclavicular lymphadenitis, 8 patients had lymphadenitis at both localizations. During the whole study period the incidence of BCG adenitis varied from 0.02% to 0.36%, while the mean rate was 0.11%±0.08% from 184,068 vaccinated children during the study period. We observed an increasing trend in the incidence of BCG lymphadenitis during the study period. The primary and complete healing rate at the end of period was 99.5% (n=193) following an affected lymph node extirpation. The mean hospitalization time after the operation was 3.71±0.18 days.

CONCLUSIONS

The incidence of BCG-SSI(®) vaccine associated purulent lymphadenitis varied widely with an increasing trend, followed by the return to the product characteristic limits. Indications for the surgical treatment should not be changed. Extirpation of the purulent BCG adenitis is a safe treatment method and leads to the primary wound healing in the majority of cases.

Post-Vaccination Disseminated Bacillus Calmette Guerin Infection Among Children in Southern Iran

Background:

Disseminated bacillus calmette guerin (BCG) infection is a rare but life threatening complication of BCG vaccination. It has been mainly seen in severe immune deficiency. A precise and rapid diagnosis is crucial for prompt initiation of an aggressive anti-mycobacterial treatment. Polymerase chain reaction (PCR) is directly applicable to smear-positive clinical specimens, proven to be a rapid and specific diagnostic test.

Objectives:

The aim of this study was to investigate disseminated BCG infection among 34 children in southern Iran, mainly confirmed by PCR.

Patients and Methods:

We included all the patients hospitalized with disseminated BCG infection at a referral teaching hospital in southern Iran between years 1990 and 2007. The clinical and laboratory data including the immunological workups were obtained through a review of the medical files. We recalled all pathology samples from pathology specimen banks and used an in-house PCR specific for Mycobacteriumbovis BCG substrain to confirm the diagnosis.

Results:

From the total of 34 children hospitalized with disseminated BCG infection, 21 were categorized as definite and 13 probable. Thirty-one patients (91%) were under two years of age and 41% were male. The most common clinical findings were fever in 31 (91.2%), axillary’s lymphadenopathy in 26 (76.5%), hepatosplenomegaly in 25 (73.5%), stunted growth in 21 (61.8%), and distant lymphadenopathy in 16 (47.1%). Polymerase Chain Reaction positivity rate was 100% (9 of 9) in bone marrow smear slides and 84.2% (16 of 19) for formalin-fixed and paraffin-embedded tissue specimens. Immunodeficiency state was detected in 50% and the overall mortality rate was 58.8% (20 of 34).

Conclusions:

Disseminated BCG infection should be considered in the differential diagnosis of infants and young children with fever, hepatosplenomegaly, lymphadenopathy, and history of BCG vaccination. The PCR method has a high positivity rate and can serve as a useful tool for the rapid and specific identification of M. bovis BCG substrain infection.

Risk Factors for Central Nervous System Tuberculosis

OBJECTIVES

To describe the epidemiology and factors associated with pediatric central nervous system (CNS) tuberculosis (TB) in California from 1993 to 2011.

METHODS

We analyzed California TB registry data for persons aged ≤18 years, comparing CNS TB cases versus non-CNS TB cases reported from 1993 to 2011. Factors associated with CNS TB and TB deaths were identified by using multivariate logistic regression.

RESULTS

A total of 200 CNS TB cases were reported. Compared with non-CNS TB case patients, CNS TB case patients were more likely to be aged <5 years (72.0% vs 43.6%; odds ratio [OR]: 3.8 [95% confidence interval (CI): 2.4-5.9]), US-born (82.0% vs 58.2%; OR: 3.3 [CI: 2.3-4.7]), and Hispanic (75.0% vs 63.2%; OR: 1.7 [CI: 1.3-2.4]). Among US-born CNS TB case patients (during 2010-2011), 76.5% had a foreign-born parent. Tuberculin skin test results were negative in 38.2% of 170 CNS TB cases tested. In multivariate analysis, age <5 years (adjusted odds ratio [aOR]: 3.3 [CI: 2.0-5.4]), US birth (aOR: 1.8 [CI 1.2-2.7]), and Hispanic ethnicity (aOR: 1.5 [CI: 1.1-2.1]) were associated with an increased risk of developing CNS TB. For deaths, CNS TB (aOR: 3.8 [CI: 1.4-9.9]) and culture positivity (aOR: 6.2 [CI: 2.2-17.3]) were associated with increased risk of death, whereas tuberculin skin test positivity (aOR: 0.1 [CI: 0.04-0.2]) was associated with decreased risk.

CONCLUSIONS

Subsets of children are at increased risk for CNS TB in California and may benefit from additional prevention efforts.

Adverse reactions to Mycobacterium bovis bacille Calmette-Guérin vaccination against tuberculosis in Iranian children

Purpose

There are considerable variations in the number of adverse reaction reports related to vaccine from different countries. The aim of this study was to review the development of adverse reactions to bacille Calmette-Guérin (BCG) vaccination among hospitalized patients in an Iranian referral hospital.

Materials and Methods

We identified hospitalized patients with BCG complications in Pediatric Infectious Disease Research Center, Tehran University of Medical Sciences, Tehran, Iran during January 2007-April 2009. Data on demographics, clinical features, laboratory findings, personal history (including vaccination history), family history, and outcomes were retrieved from medical records.

Results

There were 46 cases with BCG complication during the 2 years period. All of the children received vaccination at birth. Twenty-eight patients (61%) were male. The mean age of the patients was 13.5 ±11.3 months (range, 1 to 52 months; median, 10 months). The majority of children (57%) with BCG complication were less than 1 year old. Among hospitalized patients due to BCG complications, suppurative lymphadenitis was occurred in 28 children (61%) and lymphadenopathy was seen in 9 children (20%). Disseminated BCG was detected in 8 patients (17%) and only 1 child (2%) was presented with abscess. In 7% (n = 3) of children, the family history of BCG complications were positive.

Conclusion

The most common side effect of the BCG vaccine in our study was suppurative lymphadenitis. Disseminated BCG infection in complications leading to hospitalization in our study was 17%. With regard to the difficulty in implementing such a guideline in settings where BCG is given to all newborns, registration of Iranian primary immunodeficiency disorders (PID) patients would be helpful to increase the awareness of medical community of Iran to investigate underlying disease. In addition, BCG vaccination should postpone in each newborn with a family history of PID until the definite condition has been ruled out.

BCGitis in a patient with transient hypogammaglobulinemia of infancy

Reactions to the Bacille Calmette-Guerin (BCG) vaccine are not uncommon and have been reported in association with immunodeficiency syndromes. We report a case of an infant developing a localized BCG reaction, confirmed histologically, associated with transient hypogammaglobulinemia of infancy. Conservative management of localized BCG reactions is appropriate in most cases.

Safety and reactogenicity of BCG revaccination with isoniazid pretreatment in TST positive adults

RATIONALE

Global tuberculosis (TB) control may require mass vaccination with a new TB vaccine, such as a recombinant bacille Calmette Guerin (BCG) or attenuated Mycobacterium tuberculosis (MTB). The safety profile of live mycobacterial vaccines in latently infected adults with prior infant BCG vaccination is unknown.

OBJECTIVES

Evaluate safety and reactogenicity of BCG revaccination, with or without isoniazid (INH) pretreatment, in adults with latent MTB infection (LTBI).

METHODS

Eighty-two healthy, HIV uninfected, South African adults, with a BCG scar and tuberculin skin test (TST) diameter ≥ 15 mm, were randomized to receive 6 months of INH, starting either before, or 6 months after, intradermal revaccination with BCG Vaccine SSI (Statens Serum Institut, Copenhagen). Safety and reactogenicity data are reported through 3 months post BCG revaccination.

RESULTS

Baseline characteristics were similar between treatment arms. Mean baseline TST diameter was 20 ± 4 mm. Seventy-two subjects received BCG revaccination. Injection site erythema (68%) and induration (86%) peaked 1 week after revaccination. Ulceration (76%) peaked at 2 weeks, and resolved by 3 months in all but 3 subjects. Diameter of ulceration was >10mm in only 8%, but a residual scar was common (85%). No regional lymphadenitis or serious morbidity related to BCG was seen. Reactogenicity was not affected by INH pretreatment.

CONCLUSION

BCG revaccination of MTB infected adults is safe, well tolerated, and reactogenicity is similar to that of primary BCG vaccination. Clinical trials of live recombinant BCG or attenuated MTB vaccines may be considered in latently infected adults, with or without INH pretreatment (ClinicalTrials.gov identifier: NCT01119521).

Treating BCG-induced disease in children

BACKGROUND

Bacillus Calmette-Guerín (BCG) is a live attenuated vaccine to prevent tuberculosis, routinely administered at birth as part of the World Health Organization global expanded immunisation programme. Given intradermally, it can cause adverse reactions, including local, regional, distant and disseminated manifestations that may cause parental distress. Rarely, it can cause serious illness and even death. Among those patients with immunocompromised conditions, such as the human immunodeficiency virus (HIV) infection, the complication rate is even higher.

OBJECTIVES

To assess the effects of different interventions for treating BCG-induced disease in children.

SEARCH METHODS

The following databases were searched: the Cochrane Infectious Diseases Group Specialized Register and Cochrane Central Register of Controlled Trials (CENTRAL), published in The Cochrane Library (The Cochrane Library 2012, Issue 4); MEDLINE (1966 to November 2012); EMBASE (1947 to November 2012); and LILACS (1980 to November 2012). The metaRegister of Controlled Trials (mRCT) and the WHO trials search portal. Conference proceedings for relevant abstracts and experts were also contacted to identify studies. No language restrictions were applied.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing any medical or surgical treatment modality for BCG-induced disease in children.

DATA COLLECTION AND ANALYSIS

Two authors independently evaluated titles, applied inclusion criteria, and assessed the risk of bias of studies. The primary outcomes were the failure rate of therapies for all types of BCG vaccine-induced complications and the time to resolution of illness measured in months. The secondary outcomes were death from BCG vaccine-induced disease and the all-cause mortality. Risk ratios (RRs) were used as measure of effect for dichotomous outcomes and mean differences for continuous outcomes.

MAIN RESULTS

Five RCTs analysing 341 children addressed the primary outcomes and were included. Four arms compared oral antibiotics to no intervention or placebo, one arm evaluated needle aspiration compared to no intervention, and another evaluated the use of locally instilled isoniazid versus oral erythromycin.Two small studies evaluated oral isoniazid; we are uncertain of whether this intervention has an effect on clinical failure (RR 1.48; 95% Confidence Interval (CI) 0.79 to 2.78; 54 participants, two studies, very low quality evidence). Similarly, for oral erythromycin, we are uncertain if there is an effect (clinical failure RR 1.03; 95% CI 0.70 to 1.53; 148 participants, three studies, very low quality evidence), and for oral isoniazid plus rifampicin (clinical failure, RR 1.20; 95% CI 0.51 to 2.83; 35 participants, one study, very low quality evidence).In patients with lymphadenitis abscess, needle aspiration may reduce clinically persistent BCG-induced disease at 6 to 9 months of follow-up (RR 0.13; 95% CI 0.03 to 0.55; 77 participants, one study, low quality evidence). In another study of patients with the same condition, aspiration plus local instillation of isoniazid reduces time to clinical cure compared to aspiration plus oral erythromycin (mean difference 1.49 months less; 95% CI 0.82 to 2.15 less; 27 participants, one study).No RCTs of HIV-infected infants with a BCG-induced disease evaluated the use of antibiotics or other therapies for reducing the rate of clinical failure or the time to clinical resolution. No data on mortality secondary to the interventions for treating BCG-induced disease were reported.

AUTHORS' CONCLUSIONS

It is unclear if oral antibiotics (isoniazid, erythromycin, or a combination of isoniazid plus rifampicin) are effective for the resolution of BCG-induced disease. Most non-suppurated lymphadenitis will resolve without treatment in 4 to 6 months. Patients with lymphadenitis abscess might benefit from needle aspiration and possibly local instillation of isoniazid could shorten recovery time. Included studies were generally small and could be better conducted. Further research should evaluate the use of needle aspiration and local instillation of isoniazid in fluctuant nodes. Therapeutic and preventive measures in HIV-infected infants could be important given the higher risk of negative outcomes in this group.

Cutaneous complication after BCG vaccination: case report and review of the literature

The bacille Calmette-Guérin (BCG) vaccination protects against tuberculosis (TB)-related meningitis and disseminated tuberculosis. While severe complications after BCG vaccination are relatively rare, different cutaneous reactions have been reported. We report a patient with a 7-mm erythematous nodule at a distance of 4 cm from the BCG injection site. Histopathologically, a necrotizing granulomatous reaction pattern was seen in the dermis. Although complementary stainings did not detect acid fast bacilli, we suspected the lesion was caused by the attenuated strains of Mycobacterium bovis from the vaccine. This specific complication is called BCG-itis in the literature. After the excisional biopsy, the lesion disappeared and further treatment was not necessary. In defining the best treatment for this boy, we discovered a lack of knowledge on BCG-related lesions and their subsequent treatment options in the literature. We will list existing literature on this topic and demonstrate that treatment of BCG-related complications is poorly defined.

Ag85B DNA vaccine suppresses airway inflammation in a murine model of asthma

Background

In allergic asthma, Th2 lymphocytes are believed to play important roles in orchestrating airway eosinophilia and inflammation. Resetting the Th1/Th2 imbalance may have a therapeutic role in asthma. The mycobacterium tuberculosis 30-kilodalton major secretory protein (antigen 85B, Ag85B) can protect animals from M. tuberculosis infection by inducing a Th1-dominant response.

Methods

In this study, the Ag85B gene was cloned into pMG plasmids to yield the pMG-Ag85B plasmid. The expression of Ag85B gene in murine bronchial epithelia cells was detected by Western blotting and immunohistochemical staining after intranasal immunization with reconstructed pMG-Ag85B plasmids. The protective effect of pMG-Ag85B plasmids immunization in airway inflammation was evaluated by histological examination and bronchoalveolar lavage (BAL). IL-4 and IFN-γ levels in the BAL and supernatant from splenocyte culture were determined using ELISA kits.

Results

The Ag85B gene was successfully expressed in murine bronchial epithelia cells by intranasal immunization with reconstructed pMG-Ag85B plasmids. Using a murine model of asthma induced by ovalbumin (OVA), pMG-Ag85B immunization significantly inhibited cellular infiltration across the airway epithelium with a 37% decrease in the total number of cells (9.6 ± 2.6 × 10⁵/ml vs. 15.2 ± 3.0 × 10⁵/ml, p < 0.05) and a 74% decrease in the number of eosinophils (1.4 ± 0.2 × 10⁵/ml vs. 5.4 ± 1.1 × 10⁵/ml, p < 0.01) compared with the OVA-sensitized control group. There was no difference in the number of neutrophils in BAL fluid between the pMG-Ag85B group, the OVA-sensitized control group and the empty pMG group. IL-4 production was significantly decreased in the BAL fluid (32.0 ± 7.6 pg/ml vs. 130.8 ± 32.6 pg/ml, p < 0.01) and in the splenocyte supernatant (5.1 ± 1.6 pg/ml vs. 10.1 ± 2.3 pg/ml, p < 0.05) in the pMG-Ag85B group compared with the OVA-sensitized control group, while IFN-γ production was increased in the BAL fluid (137.9 ± 25.6 pg/ml vs. 68.4 ± 15.3 pg/ml, p < 0.05) and in the splenocyte supernatant (20.1 ± 5.4 pg/ml vs. 11.3 ± 3.2 pg/ml, p < 0.05).

Conclusion

In a murine model of asthma induced by OVA, intranasal immunization with pMG-Ag85B significantly reduced allergic airway inflammation with less eosinophil infiltration. This protective effect was associated with decreased IL-4 and increased IFN-γ production in the BAL fluid and in the supernatant of cultured splenocytes.

Reduced rate of adverse reactions to the BCG vaccine in children exposed to the vertical transmission of HIV infection and in HIV-infected children from an endemic setting in Brazil

We report on the adverse reactions to the Bacillus Calmette-Guérin (BCG) vaccine in BCG-vaccinated children. We examined children exposed to the vertical transmission of human immunodeficiency virus (HIV) (n = 141), who participated in a prevention program of vertical transmission, and HIV-infected children (n = 66) in a setting endemic for HIV and tuberculosis (TB) in Brazil from August 2000 to February 2008. No cases of disseminated BCG disease occurred in either group of children. While no cases of regional BCG disease were noted in exposed/uninfected children, the rate of regional BCG disease in HIV-infected children was 4.5% (3/66); the three events occurred in <1-year-old children (3/17; 17.6%). One case was associated with severe immunodepression before highly active antiretroviral therapy (HAART). Two cases were manifestations of immune reconstitution inflammatory syndrome (IRIS). Among the HIV-infected children, the accrued benefits of potentially preventing severe TB outweighed the risks associated with the use of the BCG vaccine.

Adverse reactions to Mycobacterium bovis bacille Calmette-Guérin (BCG) vaccination against tuberculosis in humans, veterinary animals and wildlife species

The Mycobacterium bovis strain, bacille Calmette-Guérin (BCG) is one of the most widely used human vaccines and remains one of the safest vaccines available. It has been used in human populations for over 80 years and 100 million children receive the vaccine annually. It has also been employed extensively for vaccine studies in laboratory animal hosts and is currently being developed for use in a variety of livestock and wild animals. Despite the large number of doses delivered since is first usage in 1921, reports of adverse reactions arising from the use of the BCG vaccine are relatively uncommon and where serious reactions do occur they are often the result of vaccination of immuno-compromised individuals. Factors that may influence the development of adverse reactions to BCG include the potency and dose of the vaccine strain, the route of delivery, the age and immune status of the host, and the skill levels of the operator administering the vaccine. Circumstances affecting the notification of adverse reactions include the lack of clear case definitions of abnormal vaccine reactions, and a scarcity of systematic surveillance and functioning reporting systems. With continued use of the BCG and the development of a new generation of prophylactic and therapeutic vaccines against tuberculosis in different host species, the risk factors associated with adverse reactions may need to be reappraised.

Adverse reaction to Bacille-Calmette-Guérin vaccine in a HIV positive healthcare worker

BACKGROUND

The Bacille-Calmette-Guérin (BCG) vaccine is used in Mycobacterium tuberculosis prophylaxis in at risk tuberculin-negative healthcare workers. Its use is contraindicated however in individuals with HIV infection.

AIMS

We herein highlight the case of a healthcare worker who developed a localised reaction at a BCG vaccination site and who was subsequently found to be HIV positive.

CONCLUSION

This case emphasises the importance of eliciting risk factors for immunocompromise in individuals for whom BCG vaccination is being considered.

Enquête sur les effets secondaires locaux du vaccin intradermique BCG-SSI® chez l'enfant de moins de six ans en France

During April 2006, 579 physicians took part in a survey about intradermal BCG SSI adverse events (AE) in children less than 6 years old, managed by InfoVac France. Since January 2006, 68% physicians (paediatricians: 73% and general practitioners [GP]: 60%) have vaccinated at least one child. The site of injection is mainly the extern side of the shoulder (72%), according to the recommendations. Systematic vaccination is continued by 54% GP and 26% paediatricians. Others indications are: admission in day care center (33%), admission in day care center associated with risk factors (24%), or only risks factors (8%). Half physicians observed AE and 6% of them reported them at pharmacovigilance centers or pharmaceutical company. AE were mainly inflammations or indurations over 1 cm (for 75% of physicians who observed AE), oozing (73%). Abscesses are notified by 54%, ulcers by 39%, lymphadenopathies over 1 cm by 20%, suppurative lymphadenopathies by 3% and keloid scares by 17% of them, several AE may coexist for some children. Our aim is to start a prospective follow-up of BCG-SSI vaccination and its AE; 58% physicians who answered this investigation agreed to participate.

The benefits and risks of bacille Calmette-Guérin vaccination among infants at high risk for both tuberculosis and severe combined immunodeficiency: assessment by Markov model

BACKGROUND

Bacille Calmette-Guérin (BCG) vaccine is given to Canadian Aboriginal neonates in selected communities. Severe reactions and deaths associated with BCG have been reported among infants born with immunodeficiency syndromes. The main objective of this study was to estimate threshold values for severe combined immunodeficiency (SCID) incidence, above which BCG is associated with greater risk than benefit.

METHODS

A Markov model was developed to simulate the natural histories of tuberculosis (TB) and SCID in children from birth to 14 years. The annual risk of tuberculous infection (ARI) and SCID incidence were varied in analyses. The model compared a scenario of no vaccination to intervention with BCG. Appropriate variability and uncertainty analyses were conducted. Outcomes included TB incidence and quality-adjusted life years (QALYs).

RESULTS

In sensitivity analyses, QALYs were lower among vaccinated infants if the ARI was 0.1% and the rate of SCID was higher than 4.2 per 100,000. Assuming an ARI of 1%, this threshold increased to 41 per 100,000. In uncertainty analyses (Monte Carlo simulations) which assumed an ARI of 0.1%, QALYs were not significantly increased by BCG unless SCID incidence is 0. With this ARI, QALYs were significantly decreased among vaccinated children if SCID incidence exceeds 23 per 100,000. BCG is associated with a significant increase in QALYs if the ARI is 1%, and SCID incidence is below 5 per 100,000.

CONCLUSION

The possibility that Canadian Aboriginal children are at increased risk for SCID has serious implications for continued BCG use in this population. In this context, enhanced TB Control--including early detection and treatment of infection--may be a safer, more effective alternative.

Bacille Calmette-Guérin vaccine-induced disease in HIV-infected and HIV-uninfected children

BACKGROUND

Bacille Calmette-Guérin (BCG)--a live, attenuated vaccine--is routinely given to neonates in settings where tuberculosis is endemic, irrespective of human immunodeficiency virus (HIV) exposure. HIV-infected infants and other immunodeficient infants are at risk of BCG-related complications. We report the presentation, treatment, and mortality of children who develop BCG disease, with emphasis on HIV-infected children. In addition, we present a revised classification of BCG disease in children and propose standard diagnostic and management guidelines.

METHODS

This retrospective, hospital-based study was conducted in the Western Cape Province, South Africa. Mycobacterium tuberculosis complex isolates recovered from children aged <13 years during the period of August 2002 through January 2005 were speciated by polymerase chain reaction to confirm Mycobacterium bovis BCG. Clinical data were collected through medical file review. BCG disease was classified according to standard and revised disease classifications. Mortality was assessed at the end of the study period.

RESULTS

BCG disease was diagnosed in 25 children; 22 (88%) had local disease, and 8 (32%) had distant or disseminated disease; 5 children (20%) had both local and distant or disseminated disease. Seventeen children were HIV infected; 2 children had other immunodeficiencies. All 8 children with distant or disseminated disease were immunodeficient; 6 were HIV infected. The mortality rate was 75% for children with distant or disseminated disease.

CONCLUSIONS

BCG vaccination poses a risk to infants perinatally infected with HIV and to other primary immunodeficient children. The proposed pediatric BCG disease classification reflects clinically relevant disease categories in HIV-infected children. The suggested diagnostic and treatment guidelines should improve existing case management and surveillance. Prospective evaluation of management strategies for BCG disease in HIV-infected and HIV-uninfected children is essential.

Tuberculosis in children: an update

TB is a common and serious global infection that is spread exclusively from person to person. The initial infection in most healthy people leads to LTBI 95% of the time, but untreated individuals have a 5% to 10% lifetime risk for reactivating their infection to develop highly infectious cavitary pulmonary TB or extrapulmonary disease. Following primary infection progressive disease is more likely to develop in children younger than 5 years old or those who are immunocompromised, particularly those with HIV infection. The diagnosis of TB in most of the world depends on the presence of a clinical illness typical for TB in concert with radiographic changes, the presence of AFB in sputum, or a positive TST. Newer methods of in vitro stimulation of T lymphocytes from TB-infected people to produce interferon may be more accurate than a TST but have yet to be well studied in children. Treatment of children with LTBI is generally 9 months of daily isoniazid unless the child has been in contact with an adult with known isoniazid-resistant TB. For active TB, children generally are treated for 6 months with an initial 2 months of isoniazid, rifampin, and pyrazinamide. Where exposure to an isoniazid-resistant strain is likely, ethambutol is added. After 2 months, pyrazinamide is discontinued unless the patient has been confirmed to have been infected with a resistant strain of M. tuberculosis. BCG, rarely used in the United States, is still considered important to prevent meningitis and miliary disease in very young children in areas of the world with a high prevalence of TB.

Serious adverse events associated with bacille Calmette-Guérin vaccine in Canada

BACKGROUND

Targeted Bacille Calmette-Guérin (BCG) vaccination is offered to neonates in some First Nations and Inuit (FNI) communities in Canada. Serious adverse events associated with BCG vaccine prompted a review to assess causality.

METHODS

The Immunization Monitoring Program Active (IMPACT), a pediatric hospital-based active surveillance network, reported admissions for BCG-related adverse events between 1993 and April 2002. The Canadian Advisory Committee on Causality Assessment (ACCA) reviewed the reports to assess causality. Data between 1987 and September 2002 from the Vaccine-Associated Adverse Event Surveillance (VAAES) Program, a passive national reporting system, were also reviewed.

RESULTS

IMPACT identified 21 pediatric cases; 19 were Canadian-born, and 18 were FNI. Six disseminated BCG cases were identified; 5 were FNI infants who subsequently died. All had immunodeficiencies and concurrent infections. Other adverse events included 2 cases of osteomyelitis, BCG abscesses and lymphadenitis. ACCA reviewed the 21 cases and determined that 14 were very likely associated with the vaccine, including the 6 disseminated BCGs; 5 were probably associated and 1 was possibly associated with the vaccine; 1 was unclassifiable. The VAAES program identified 157 adverse events. No additional serious systemic adverse events (disseminated BCG or osteomyelitis) were identified.

CONCLUSIONS

Serious BCG vaccine-associated complications continue to occur in Canada. The numbers of FNI children with disseminated disease was greater than expected from reported rates in the literature.

Acute care issues in internationally adopted children

Over the past decade there has been a dramatic increase in international adoptions in the United States. While most adopted children will have common illnesses, others may have unique medical issues as a result of the conditions in their birth country requiring a broadened differential diagnosis. Knowledge of these issues is essential in the management of these patients. This review will predominately focus on infectious disease issues commonly seen in international adoptees but will also discuss other medical conditions and some of the psychosocial issues which may be encountered by caregivers in the emergency department.